Parts

IDs | Numbers | Names

A part is a scriptable user interface element.

Buttons, fields, cards, backgrounds and the stack itself are parts. Menus and windows are also controllable via HyperTalk, but you cannot attach a script directly to them. See the section below for details about controlling the menu bar.

Every part maintains a set of properties that describe its look-and-feel (like its size, location and style). Modifying a part's properties changes the way the part looks and behaves.

Parts may be addressed in HyperTalk by their name, number, or ID, and a part can refer to itself as me. You can refer to buttons and fields on other cards, other backgrounds, or even in other stacks, too. For example, get the width of card button "Push Me" of card 3 of background id 2 of stack "Cool Stuff".

Part IDs

In WyldCard, each part in the stack is assigned a ID (unique to that stack) which never changes and will never be reused (even if the part is deleted). Be aware that HyperCard and WyldCard differ in the way they generate and assign part IDs; WyldCard's IDs might not look exactly like HyperCard's.

For example:

hide card button id 0
put "I like IDs" into background field id 22 of card 3

Part Numbers

A part's number represents its logical order in the collection of other parts of the same type.

For buttons and fields, their part number represents their drawing order (z-order) on the card or background on which they appear. Higher numbered parts are drawn before lowered numbered parts and thereby appear behind them. Use the "Bring Closer" or "Send Further" commands in the "Objects" menu to change a button or field's number.

For cards and backgrounds, their number represents their position in the stack. Card number 1 is the first card in the stack, card number 2 is the second, and so forth. Backgrounds are similarly numbered by their first appearance in the stack. You can refer to fields and buttons relative to all other parts on the same layer of the card (background part 14) or relative to other parts of the same type (bkgnd button 13 or bkgnd field 3).

For windows, HyperCard assigned their number based on the window's front-to-back position. However, WyldCard assigns windows a number based on their title's alphabetical order (a limitation imposed by the multi-platform windowing systems that WyldCard supports).

You cannot directly change the number of a part by setting its number property. For example, set the number of this card to 10 is illegal.

A few examples:

add 20 to the height of card button 1.
set the name of background part 9 to "Number 9"   -- might be a card or a field
hide window 4

Note that button 1 refers to button number one, whereas button "1" refers to the button named "1".

Part Names

Every part has a name which can be edited by the stack author or changed via script. Because parts are not required to have unique names, the part with the lowest number will be assumed when referring to a name shared by multiple parts.

get the height of background button "My Neat Button"
put "2 * 2 = 4" after card field "Math" of the first card